Acar is moving in uniform circular motion. if the car's speed were to double to keep the car moving with the same radius, the acceleration would

increase by a factor of 2
increase by a factor of 4
decrease by a factor of 2
decrease by a factor of 4

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.